textproduct: Albany

WHAT HAS CHANGED

Confidence has increased in valley areas seeing little to no snow tonight, so snowfall totals were decreased further from the previous forecast. Additionally, wind gusts Thursday afternoon through Thursday night were increased due to increased confidence in deep mixing and terrain influence.

KEY MESSAGES

1) Widespread, nuisance precipitation this afternoon through tonight will wet walking and road surfaces that will freeze overnight and pose potentially hazardous travel conditions for tomorrow morning's commute.

2) Snow beginning in the Southwest Adirondacks late this afternoon will linger through early Friday morning, bringing moderate snowfall accumulations and potentially difficult travel due to snow covered roads and reduced visibility at times.

3) Additional chances for precipitation lie ahead for the weekend and into early next week, but significant impacts are not expected at this time.

DISCUSSION

KEY MESSAGE 1...

A surface cyclone currently resides in central Quebec with a broad surface trough and associated cold front draped to the south and west just upstream of our CWA. Aloft, the axis of a large- scale, positively tilted trough extends from the western Great Lakes through the Deep South with moist, southwesterly flow surging northward about its forward flank. With just enough forcing present, patchy light rain has started across portions of eastern New York and western New England this afternoon and is expected to continue into tonight.

Showery rain is anticipated to congeal into a stratiform precipitation shield within the next several hours, though with several disturbances to our south beginning disrupting moisture transport into our region this evening, rates will remain very light. Additionally, while all precipitation will begin as rain, a gradual transition to snow, particularly at higher elevations, is anticipated this evening through tonight as temperatures drop especially behind the system's cold front.

It has become increasingly likely that valley areas will see very little snow as the loss of moisture will likely precede the transition from rain to snow in these areas. However, upslope flow will help keep the column moist for higher terrain areas where an easier transition to snow will occur. That said, very little in the way of accumulation is anticipated outside of the Southwest Adirondacks where lake effect/lake enhanced snow will lead to moderate accumulations. Elsewhere, a couple of tenths to about 1.5" is anticipated.

That said, walking and road surfaces will become wet even from the light precipitation this afternoon through tonight. With light winds anticipated tonight and temperatures falling below freezing in the wake of the cold front, these surfaces will freeze, possibly fairly quickly especially around the morning commute tomorrow morning. Therefore, travel conditions for tomorrow's morning commute could be difficult to hazardous especially where roadways go untreated.

KEY MESSAGE 2...

While the Southwest Adirondacks will likely see some rain initially this afternoon, a quick transition to snow is anticipated this evening. Moist, cyclonic, upslope flow will maintain snow throughout the overnight period while other areas dry out. Then, late tonight in the wake of the cold front, lake effect snow showers will develop and linger through tomorrow to add to accumulations further.

By tomorrow evening, accumulations across the Southwest Adirondacks will range from 2-5 inches. The expectation for these moderate snowfall totals, in addition to the potential for difficult travel and reduced visibilities at times, warranted the maintaining of the previously issued Winter Weather Advisory that goes into effect at 7 PM this evening and lasts through 7 PM tomorrow.

KEY MESSAGE 3...

While dry conditions largely return for Friday, an unsettled pattern is generally expected for the weekend and into early next week. Based on the latest guidance, there is not a large concern for any significantly impactful weather, but rather just nuisance precipitation much like what is expected today into tonight.

There is a storm we are closely monitoring that falls to the Sunday evening through Monday timeframe. Medium-range guidance hints at a Nor'Easter that will track fairly close to the East Coast. However, for the most part, models are keeping this system far enough east to pose little concern to our CWA. In fact, most ensembles favor a farther-east track that would keep us completely dry. That said, some of the latest deterministic runs do push the track a little farther west which would bring snow to at least the eastern half of our area. We will continue to keep a close eye on this storm and alter the forecast and messaging if it seems more probable that we could be impacted by it.

AVIATION /00Z THURSDAY THROUGH MONDAY/

As a frontal system approaches, a steady light rainfall has developed over the entire region. Latest observations show rainfall has begun at all TAF sites, although it is initially having only a limited impact on visibility, with most sites still seeing VFR flying conditions. However, KPSF and KPOU have started to see brief reductions in visibility and visibility will be lowering through the evening for all sites. Most sites should see a period of IFR flying conditions (mainly for ceilings, although briefly lower visibility is possible as well) towards midnight. Ceilings may get as low as 900 feet for all sites.

Steady rainfall will taper off around 07z-09z for all sites. Rain may briefly end as wet snow at KGFL for an hour or two at the end, which could briefly lower visibility to around 2SM or so. Once precip ends, visibility should improve for all sites. Ceilings may take longer to go up, initially to MVFR and eventually to VFR for the valley sites by the mid to late morning or so, as drier air works into the region from the west.

As the front passes, winds will switch to the southwest for the late night hours and eventually the west for during the day on Thursday. Winds will increase to around 10 kts by the late morning on Thursday with some higher gusts possible, especially for KALB and KSPF, especially in the afternoon hours.

Outlook...

Thursday Night: Low Operational Impact. Breezy. NO SIG WX. Friday: Low Operational Impact. Breezy. NO SIG WX. Friday Night: Low Operational Impact. Slight Chance of SN. Saturday: Moderate Operational Impact. Chance of SN. Saturday Night: Moderate Operational Impact. Chance of SN. Sunday: Low Operational Impact. Slight Chance of SN. Sunday Night: No Operational Impact. NO SIG WX. Martin Luther King Jr Day: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...Winter Weather Advisory until 7 PM EST Thursday for NYZ032-033. MA...None. VT...None.